And robt



TINITED STATES PATENT OFFICE.

HORACE L. HERVEY, OF QUINGY, ILLINOIS, AND ROBT. E. OSBORN, OFSPRINGFIELD, OHIO.

BRIDGE.

Specification of Letters Patent No. 13,461, dated August 21, 1855.

To all whom t may concern Be it known that we, HORACE L. HERvEY ofQuincy, in the county of Adams and State of Illinois, and ROBERT E.OsisoRN, of Springfield, in the county of Summit and State of Ohio, haveinvented certain new and useful Improvements in Bridges and we do herebydeclare that the same are described and represented in the followingspecification and drawings.

To enable others skilled in the art to make and use our improvements wewill proceed to describe their construction and use, referring to thedrawings in which the same letters indicate like parts in each of thefigures.

Figure l, is an elevation of one side of our improved bridge. Fig. 2, isa plan showing the floor timbers and the lateral cables. The otherfigures in the drawing will be referred to in the specification.

The nature of our invention consists in arranging the abutmentsuspension blocks so as to traverse on the abutments in combination withan adjustable suspension truss and an arched truss, so that the camberof the bridge may be increased or diminished in connection with thetension chord, so as to increase the strength of the bridge by lesseningthe strain on any one point and distributing it to many points. Also inso constructing and arranging the blocks which sustain the tensionbraces of the tower or suspension section, that theyl will slide on thestring pieces, so as to equalize, distribute and proportion the loadmore uniformly and over a larger portion of the bridge. And further insupporting the Hoor timbers alternately or successively by the arch andsuspension trusses.

In the accompanying drawings A, A, are the abutments or towerssupporting the bed plates B, B, which bed plates are provided with aseries of rollers O, C, as represented in Fig. 3, upon which thesuspension blocks D, D, rest and traverse. One of the suspension blocksis represented in Fig. 4. The suspension cables, which may be made ofwire in the usual manner, one of which is seen at E, passing around theblocks D, D, and supporting the lower or suspension truss frame by meansof the flanges or projections F, F, on the boxes G, G, which boxessurround the posts H, H, the flanges resting on the cables. One of theboxes G G is represented in Fig. 5. They are fitted to move up and downupon the posts H, H.

The upper ends of the posts H, H, are provided with metal sockets I, I,one of which is shown in Fig. 6, provided with flanges (a, a, to embracethe stringers or chords, J, J, below the floor timbers K, K, whichstringers have their ends resting in the abutments A, A. The floortimbers L, L, which are sustained by the upper or arch truss are placedupon the chords J, J, alternately between the timbers K, K; and thechords M, M, are laid across both sets of floor timbers as representedwith their ends resting in the abutments A, A.

There are some metal plates ZJ, Z1, placed on the chords M M for theblocks c, o, which sustain the suspension braces N, N, of the suspensiontruss, to rest and traverse upon. The suspension braces N, N, arearranged as represented and secured to each abutment by the eye bolts(l, cl, and pass alternately over the blocks c, c, and under the socketse, e, upon the lower ends of the posts H, H, which sockets are made soas to surround the foot of the posts and provided with an opening f, inthe bottom for the escape of moisture, as represented in Fig. 7. Thesesuspension braces N N are made in separate p ieces of convenient lengthsand connected together by swivel links g, g, wit-h a female screw in oneend fitted to the male screws on the ends of the braces, so as to loosenor tighten them as required.

There are some short posts O, O, placed each side of the suspensiontruss frame between the flanges F, F, (on the boxes G, G,) and the floortimbers K, K, so that the suspension truss frame and cables E, E, mayunitedly sustain the load upon the bridge.

The posts R R of the arch truss frame are provided with metal sockets I,I, like the one represented in Fig. 6, with flanges to embrace thechords M M right over the floor timbers L, L; the socketson the upperends of the posts embracing the chords S, S, right under the upper floortimbers T, T, which rest upon the chords S, S, as represented.

There are a series of triangular metal blocks L, it, placed on thechords S, S, each side of the floor timbers T, T, and under the chordsM, M, each side of the floor timbers L, L, which blocks are perforatedfor the suspension braces U U of the arch truss frame which are providedwith screw nuts which are screwed up against the blocks h, 7L, tosupport the arch truss frame. One of the blocks L, h, is shown in Fig.8, provided with a flange z', which is inserted in a mortise made toreceive it in the ioor timbers TT, and L, L. There is a series of floortimbers V, V, placed half way between the timbers T, T; and the archstringers W, W, are put on the top of all the timbers, and a hole boredthrough the stringer and timber V; and a metal plate X put under thechords S, S, and bolts are put through the plates timbers and stringersso as to clamp the whole firmly together as represented in the drawing.The ends of the chords S, S, and

' arch stringers l/V, W, are iitted to the recesses Y, in the suspensionblocks D, D. There are a series of braces j, j, framed in between thefloor timbers K K and L, L, as represent-edv in the drawing Fig. 2, anda similar set of braces between the floor timbers T, T, and V, V. Y

There are some scores cut across the iioor timbers K, K, and L L for thelateral cables Z, Z, which cables prevent the bridge from vibratingsidewise and make it very firm, and support it against the pressure ofthe wind, and any motion sidewise that the loads passing over might havea tendency to give it. The lateral cables Z, Z, are fastened to theabutments A, A, by the eye bolts 7c 7c which extend through theabutments.

The abutment blocks D D being on rollers move readily and admit of thediminution of the camber of the upper chords S, and W, when the load ispassing over the bridge which they would not do if the blocks D, D, werepermanent. But the ofce of the tension chord E is to increase thestiffness of the arched truss by preventing the diminution of the camberin the upper chords; and if this tension chord was so made and adjustedthat its extremities at (D D) should always be at the exact distancethey now are from each other, it is evident the camber of the upperchords must be unchanged. But the tension chord being in this case anendless one; and always of the same length; the adjustment of the camberof the bridge is effected by making the abutment blocks traverse withinthe tension chords, and the blocks c, c, to traverse on the chords M, M,thereby allowing the tension chord E, to become more or less arched toadapt itself to the degree of camber given to the trussed arch orbridge. In the usual combination of the arched truss with the tensionchord the struts corresponding to O, O, are fixed; and the tension chordis tightened or loosened by means of screws which throws the principalstrain on those points at the bridge immediately over the strutscorresponding to O, O.

By the above described construction and arrangement the suspensioncables support the suspension truss, and when the bridge is loaded theweight tends to draw the suspension blocks toward each other, whichtends to spring up the arch truss, and in the several parts of thebridge unite in sus.

taining and supporting it.

By, making the suspension blocks of theY cables, and the suspensionblocks of the suspension braces, to traverse, we compel each part of thebridge to sustain and support its proper proportion of the load, anddistribute the strain or weight of the load more uniformlyY over theseveral parts of the bridge, without compelling any particular part tosustain more than its proper share.

By the use of metal sockets at the joining with openings for the escapeof moisture the tendency to decay is very much lessened.

We believe we have described the construction and use of ourimprovements, so as to enable any person skilled in the art to make anduse them, we will now specify what we desire to secure by LettersPatent.

We claiml. The arrangement of the blocks D D and posts O, O, incombination with the adjustable suspension truss the arched truss andthe tension chord E, so that the camber of the bridge may be increasedor diminished by the adjustment of these blocks in connection with thetension chord E, so as to increase the strength of the bridge bylessening the strain on any one point, by distributing it to manypoints, by means of the adjustable blocks substantially as described.

2. We claim constructing and arranging the blocks c, c, which sustainthe tension braces of the suspension truss so that they will slide ortraverse on the string pieces M, M, substantially as described; so as toequalize, distribute and proportion the load more uniformly and over alarger portion of the bridge.

3. We claim supporting the floor timbers K, K, and L L alternatelyorsuccessively by the arch and suspension trusses substantially asdescribed.

HORACE L. HERVEY. ROBERT E. OSBORN.

Witnesses to the signature of Horace L. Hervey:

J. DENNIS, Jr., J oHN S. HOLLINGSHEAD.

Witnesses to the signature of Robert L. Osborn:

A. C. ANDREws, A. J. FENTON.

